A multichannel microelectrode that monitors neurochemical concentrations from many nearby brain sites simultaneously will be highly beneficial to brain researchers. Such a tool will allow scientists both to collect data more efficiently and to study the dynamics of neurochemical gradients during animal behavior within any brain structure. The aim of the proposed research is to design, develop and evaluate a multichannel microelectrode system for mass production and commercialization to the neuroscience and biomedical communities. This multichannel neurochemical recording system is called "PRONG" which stands for "Parallel Recording of Neural Groups". It includes a 24 channel microelectrode and a special connector. The proposed research will modify a working prototype of the PRONG system that has been used to record neural potentials so that it can be used for parallel voltammetry in vivo. The PRONGs will be tested for their sensitivity to dopamine concentration gradients.